When I first bought my 91/30 this was the case, but I got a new extractor and had the headspace checked. No problem now. I can almost cycle it as fast as the K31. Now shooting it that fast is something altogether different.

Theres a few things this could be due too, some ammo is harder to cycle in mine then others, if yours was a new in wrapper one it may loosen up over time also, my new m44 is stiffer then my used captured one.